[totobmw]

Ok, so only being new to the whole run flat saga, I read as much as I could on ditching the Rft's on my 135i with the idea I would also go get some 19in VMR 718s with Michellin PSS (225/35/19_255/30/19) as all I could read was how terrible the RFT's were and how better the feel and ride was with Non Rft's.

Though after having the new set up on the car for a week, I feel that, yes, it is quieter, however performance has been altered massively, to the point where I am careful on how I drive the car.

The car feels floaty and unstable. From what I have read, this is the normal for most first impressions for the reasoning of a weaker sidewall.

Though I am now at the point where I may rid of the PSS and get some 19in RFts to gain back the performance.

BMW remark 'all of our vehicles that use Run-flat technology have their suspension and braking components set up to accommodate Run-flat tyres. Should you decide to change to non Run-flats, it may alter the driving and handling characteristics of your vehicle. It is for this reason that this modification is not recommended by BMW as a manufacturer.' and may I add this is the same for most tire expert websites.

I run the tire pressures of 160KPA (40PSi) all round and though I am running 19's the rolling diameter difference is very minimal (1%) to the OEM RFTS which were running on the 261 Msport rims.
Additional to this the car is stock with the stock msport suspension.

How can I get back performance, will different pressures or springs or whatever help?